(1) Field of the Invention
Many windows for residential and commercial buildings include opening sections to allow air from an exterior of the building to enter the building, for ventilation purposes, for example. The opening sections often comprise a window pane which slides, in generally horizontal or vertical directions, in relation to a fixed pane. The panes are typically mounted in a window frame with the sliding pane being spaced from, but generally parallel to, the fixed pane, such that when the sliding pane has been moved to its open position, it is located behind the fixed pane, i.e. towards the interior of the building. Whilst windows of this nature allow a large amount of external air to enter a building, they also give rise to a number of disadvantages, principally relating to safety and security. It will be appreciated that, with the sliding pane in its fully open position, a large opening is presented, through which a person might be able to pass. This has clear security implications, in that an intruder could gain access to a building through the open window, especially where the window is at a relatively low, accessible level. Of equal importance, particularly where the windows are installed in a residential building, is the risk that a person or animal could fall or climb out of the open window, possibly leading to injury or even death.
Of course, these considerations apply not only to sliding windows, but also to doors which use the same principles of operation, such as sliding patio doors. It will be understood, in that light, that the term ‘window assembly’ as used herein is also intended to refer to, and thus encompass, patio door assemblies and the like.
Efforts have been made to address some of these drawbacks, but have hitherto proved unsatisfactory, with many employing guards of wire mesh or similar material which are simply positioned over a window opening.
(2) Description of Related Art Including Information Disclosed Under 37 CRF 1.97 and 1.98
For example, UK patent application no. 2378475 discloses a removable window guard comprising a frame which supports wire mesh and which can be clipped into place on an interior side of the window by means of clips which are attached to the frame.
Similarly, European patent application no. 0422934 discloses a window guard comprising a sheet of perforated metal attached to a frame which is receivable on an external side of a window frame and which can be fixed into position using brackets.